Electric actuator module for selectable clutch

ABSTRACT

A clutch module which includes a first rotating member including at least one strut actuation module and a second engaged member including cam surfaces thereon for engagement by said strut actuation module. The strut actuation module includes a frame with a strut pivotally movable with respect to the frame. The strut includes an engagement end and a base end including a first side and a second side thereof. A pin or post portion extends from the frame and has an insulated bobbin with an energizable coil surrounding the bobbin. A U-shaped member including a pair of actuation legs is attached to the pin member and forms a magnetic gap between the base end of the strut and peripheral ends of the legs, such that when the coil is energized the peripheral ends of the legs are polarized in a first polarity and the frame and the strut are polarized with an opposite polarity thereby biasing the strut toward the peripheral ends and pivoting the actuation end into engagement with a cam surface of the engagement member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/715,121, filed Oct. 17, 2012 which is incorporated herein byreference thereto.

FIELD OF THE INVENTION

The present disclosure relates generally to an actuation member. Moreparticularly, the present disclosure relates to a transmission for usein a drive train of a vehicle (such as an automobile truck, van,utility, industrial equipment, fleet, cargo or the like) including anactuation member for use in selectively a clutch in the transmission.

BACKGROUND OF THE INVENTION

A selectable one way clutch (OWC) to be used in automatic transmissionsreplaces the friction discs OWC actuated by oil pressure with astrut-based selectable OWC actuated by an electromagnetic modulecontrolled by the transmission ECU. This reduces the drag lossesassociated with the friction disc clutch of prior designs when it isopen and over-running continuously while the transmission is running andmay also offer cost reductions associated with the removal of thecomponents of the friction discs clutch (friction discs, pressureplates, end plate, piston and seals).

In one prior art embodiment of a clutch for a transmission, a coil iswound around a steel magnetic pole, which when electrically energized,acts to close the gap (such as an air gap) between the end poles (i.e.,north and south) and the one-way clutch strut end. In this design, thepole ends are magnetized, which work to attract the end portion of thestrut, which is not magnetized.

In the above concept, the clutch housing does not play any role in themagnetic circuit; it only controls the relative position of the coil andstruts. When an electrical charge is applied, the mechanism pulls thestrut from the open position and toward the closed position. The pole ismagnetized and the strut is not magnetized so the housing is not part ofthe magnetic circuit or path.

While this arrangement is one method of actuating a strut, it requiressingle pole magnetic attraction which is not as robust or reliable of alock up as might be desired depending on the application. Therefore, itis desirable in the art to provide a more robust actuation of a strut ina clutch.

SUMMARY OF THE INVENTION

In accordance with the present invention there is provided a clutchactuation module assembly. A clutch module which includes a firstrotating member including at least one strut actuation module and asecond engaged member including cam surfaces thereon for engagement bythe strut actuation module is provided. The strut actuation moduleincludes a frame with a strut pivotally movable with respect to theframe. The strut includes an engagement end and a base end including afirst side and a second side thereof. A pin or post portion extends fromthe frame and has an insulated bobbin with an energizable coilsurrounding the bobbin. A U-shaped member including a pair of actuationlegs is attached to the pin member and forms a magnetic gap between thebase end of the strut and peripheral ends of the legs, such that whenthe coil is energized the peripheral ends of the legs are polarized in afirst polarity and the frame and the strut are polarized with anopposite polarity thereby biasing the strut toward the peripheral endsand pivoting the actuation end into engagement with a cam surface of theengagement member.

In alternate embodiments bi-directional strut arrangements are provided.

In accordance with the present invention there is provided an improveddevice and control strategy for an OWC clutch for use in a transmissionin a vehicle wherein the housing of the clutch actuator is included aspart of the magnetic circuit for actuating the mechanism to create astronger magnetic actuator device and to provide greater accuracy andcontrol while reducing the power consumption and other negativedrawbacks of the known mechanisms and controls.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is an assembly view of the clutch showing a sectional view of astrut actuation module in accordance with the present invention;

FIG. 2 is a detailed sectional view of the actuation module of FIG. 1 ofthe present invention;

FIG. 3 is a sectional view of the actuation module of FIG. 2 taken alongline 3-3 of FIG. 2;

FIG. 4 is a detailed sectional view of the actuation module of FIG. 2;

FIG. 5 is an assembly view of the clutch showing a spaced plurality ofactuation modules in section in accordance with the present invention;

FIG. 6 is a detailed sectional view of an alternate embodiment of anactuation module showing a pair of actuated strut assemblies on a commonframe;

FIG. 7 is a detailed sectional view of an alternate embodiment of anactuation module showing a pair of actuated strut assemblies on a commonframe and demonstrating using a common coil to actuate the struts;

FIG. 8 is a sectional view of the actuation module of FIG. 7;

FIG. 9 is a detailed section view showing a pair of actuation modulesoperating in a bi-directional clutch;

FIG. 10 is an alternate embodiment of a bi-directional actuation moduleshowing a pair of coils operating a pivotal strut;

FIG. 11 is a sectional view of the bi-directional actuation module ofFIG. 10;

FIG. 12 is a sectional view of an alternate embodiment of abi-directional module using a mechanical actuation;

FIG. 13 is a perspective view of the strut member of FIG. 12.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with the present invention there is provided a clutchmodule generally shown at 10 for example for a transmission (not shown)which is controlled using an on-off relay to actuate a clutch mechanism.

Referring to the drawings, FIGS. 1-4, there are provided a clutch module10 which includes a first rotating member 12 including at least onestrut actuation module generally indicated as 14 and a second engagedmember 16 including cam surfaces 17 thereon for engagement by said strutactuation module 14. The members 12 and 14 include engagement teeth orsplines 12(a) and 14(a) respectively. The strut actuation module 14includes a frame 18 with a strut 20 pivotally movable with respect toframe 18 about a pivot 22. The strut 20 includes an engagement end 26and a base end 24 and including a first side 28 and a second side 30thereof. A pin or post portion 32 extends from said frame 18 and has aninsulated bobbin 34 with an energizable coil 36 surrounding the bobbin34. A U-shaped member 37 is secured magnetically and mechanically tosaid post 32 by way of a screw or other fastener 39. The U-shaped member37 includes a pair of actuation legs 38 and 40. A biasing spring 42(such as the accordion spring shown) is provided in a bore 44 in theframe 18. At rest the biasing spring biases the strut 20 out ofengagement with the cam surfaces 17 to provide a normally disengagedfreewheeling condition. The peripheral ends 46 and 48 form a magneticgap between said base end 24 of said strut 20 and peripheral ends 46 and48 of said legs 38 and 40.

When the coil 36 is energized the peripheral ends 46 and 48 of said legs38 and 40 are polarized in a first polarity and said frame 18 and saidstrut 20 are polarized with an opposite polarity thereby biasing saidstrut 20 toward said peripheral ends 46 and 48 and pivoting saidengagement end 26 into engagement with a cam surface 17 of saidengagement member 16.

Typically the actuation module is contained in a metallic housing. Thusin the present invention, the housing can be used as an integralcomponent of a magnetic circuit for controlling the clutch. When thecoil is powered, the housing is magnetized and will take a particularpolarity (i.e., either north or south as may be desired) that isopposite from a polarity of the magnetic poles of an actuator, in thisinstance the U-shaped member 37 coupled to the clutch mechanism. Sincethe housing is in contact with struts, the struts will be magnetizedwith the same polarity as the housing. In this application, theattraction force between the strut ends and the magnetic poles of theU-shaped member 37 (i.e., across the air gap between them) is greatlyincreased as compared with the case where the struts carry a neutralcharge from a magnetic perspective.

While the strut 20 is shown to be pivotal about a pin it is to beappreciated by those skilled in the art that the strut can be configuredas being pivotable in a suitable housing in the member 12.

As can be seen in FIG. 6, all of the coils 36 and 36 a (e.g., two in theembodiment shown) will work together to magnetize the housing, thereforeincreasing the magnetic field intensity and generating a greatermagnetic force in the struts and attracting them toward the closedposition from the open position.

Referring now to FIG. 7 there is provided an alternate embodiment of andactuation module 110. Strut actuation module 110 includes a pair ofpivotal engagement struts 112 and 114 which pivot on pins 116 and 118respectively, and are attached to frame 120. A U-shaped member 122 isprovided which includes a front U-shaped member 124 and a rear U-shapedmember 126 which are magnetically and electrically coupled to oneanother through connection leg 128. Front and Rear U-shaped members 124and 126 include a pair of outer peripheral end portions 130 and 132which engaged the struts 112 and 114 on the front and rear sides of thestruts. A single central bobbin and coil 134 energizes the U-shapedmembers for providing the actuation of the multiple struts. It will bereadily appreciated that while two struts are shown this invention couldbe configured to actuate more than just two struts if desired. As shownin FIG. 8 biasing springs are provided for biasing the struts 112 and114 into a freewheeling position.

FIG. 9 shows the use of mirror image strut actuation modules 14 and 14′of the type shown in FIGS. 1-4 and discussed above. Where the mirrorimage parts are labeled with prime numbers. The engaged member 16′ inthis embodiment includes bi-directional cam members 17′. In operation,either actuation member or sets of members 14 or 14′ can be energizeddepending on the direction which is desired for engaging and rotatingthe engaged member 16′.

Referring now to FIGS. 10 and 11 there is show a second embodiment of abi-directional arrangement 210. In this embodiment a symmetrical strutmember 212 is pivotally attached by a pin 214 to a frame 216. A pair ofU-shaped members 218 and 220 with separate coil and bobbin assemblies222 and 224 are used to selectively actuate the strut from a firstposition for actuation engaging cams and rotating the member 226 in afirst direction or the other coil is used for actuation and engagingcams for rotating the member in a second direction. Biasing springs 228and 230 are provided for biasing the strut 212 to a free-wheelingposition.

Referring now to FIGS. 12 and 13. There is provided an alternateembodiment of a two way clutch actuation module 310. In this embodimenta strut 311 is provided which is pivotal about pin 312 by way of anactuation arm 314 which is engaged by a corresponding orifice 316 in anactuation slider 318 with slides in a track 320 in frame 322. In thisembodiment the slider may be powered by any number of mechanisms such ashydraulics, pneumatics, a solenoid, a servo, a ball screw arrangement,stepper motor, or the like for moving the sliding member back and forthin the track for actuation of the strut in an opposite direction.

In a further alternate embodiment a bi-directional actuation module maybe provided by using a permanently magnetized symmetrical strut memberwith a U shaped member which has legs on either side of the pivot. Inthis embodiment frame includes a pin portion extending from the frameand having and insulated bobbin with an energizable coil surrounding thebobbin. The U-shaped member includes a pair of actuation legs attachedto said pin member and extends between a first polarized end of saidstrut and a second peripheral end of said leg being adjacent to a secondpolarized end of said strut. In this embodiment when the coil isenergized the peripheral ends of said legs are polarized for moving saidstrut to a first position and when energized in an opposite directionthe legs are polarized for moving the strut in an opposite direction.

It is understood that the above description is intended to beillustrative and not restrictive. Many embodiments as well as manyapplications besides the examples provided will be apparent to those ofskill in the art upon reading the above description. The scope of theinvention should, therefore, be determined not with reference to theabove description, but should instead be determined with reference tothe appended claims, along with the full scope of equivalents to whichsuch claims are entitled. The disclosures of all articles andreferences, including patent applications and publications, areincorporated by reference for all purposes. The omission in thefollowing claims of any aspect of subject matter that is disclosedherein is not a disclaimer of such subject matter, nor should it beregarded that the inventors did not consider such subject matter to bepart of the disclosed inventive subject matter.

What is claimed is:
 1. A clutch module comprising: A first rotatingmember including at least one strut actuation module; A second engagedmember including cam surfaces thereon for engagement by said strutactuation module; said strut actuation module including a frame with astrut pivotally moveable with respect to said frame, said strutincluding an engagement end and a base end including a first side and asecond side thereof, a pin/post portion extending from said frame andhaving and insulated bobbin with an energizable coil surrounding saidbobbin, a U-shaped member including a pair of actuation legs attached tosaid pin member and forming a magnetic gap between said base end of saidstrut and peripheral ends of said legs, such that when said coil isenergized the peripheral ends of said legs are polarized in a firstpolarity and said frame and said strut are polarized with an oppositepolarity thereby biasing said strut toward said peripheral ends andpivoting said actuation end into engagement with a cam surface of saidengagement member.
 2. The clutch module of claim 1 further wherein thestrut is pivotable around a pin secured to the frame.
 3. The clutchmodule of claim 1 wherein the strut is pivotable in a pocket formed inthe first driven member.
 4. The clutch module of claim 1 furthercomprising a plurality of said actuation modules.
 5. The clutch moduleof claim 4 wherein said plurality of actuation modules are positionedtogether on a single frame member for increasing the magnetic force. 6.The clutch module of claim 5 where a single coil is used to operate aplurality of struts.
 7. The clutch module of claim 1 wherein a pluralityof first cam surfaces are formed on said second engaged member forengagement of said engaged member in a first direction and a secondplurality of cam surfaces are formed on said engaged member forengagement of said engaged member in a second direction and furthercomprising at least one actuation module for selectively engaging saidfirst or second cam surfaces.
 8. The clutch module of claim 7 whereinsaid strut of said actuation module is pivotal in a first direction forengaging said one of said first plurality of cam surfaces and pivotal ina second direction for engaging one of said second plurality of camsurfaces.
 9. The clutch module of claim 7 wherein a first coil is usedfor pivoting said strut in a first direction and a second coil is usedfor pivoting said strut in a second direction.
 10. A bi-directionalclutch module comprising: A first rotating member including at least onestrut actuation module; A second engaged member including a plurality offirst cam surfaces formed on said second engaged member for engagementof said engaged member in a first direction and a second plurality ofcam surfaces are formed on said engaged member for engagement of saidengaged member in a second direction and when said at least oneactuation module is configured for selectively engaging said first orsecond cam surfaces. said strut actuation module including frame with astrut pivotally moveable with respect to said frame, said strut of saidactuation module is pivotal in a first direction for engaging said oneof said first plurality of cam surfaces and pivotal in a seconddirection for engaging one of said second plurality of cam.
 11. Thebi-directional clutch module of claim 11 wherein said strut furthercomprises a control arm extending from a lower portion of said strutsaid frame including and actuation portion for engaging said control armand pivoting said strut from a first position for engaging said engagedmember for rotation in a first direction and a second position forfreewheeling of the clutch and a third position for engaging saidengaged member for rotation in a second direction.
 12. The bidirectionalclutch module of claim 12 wherein the actuation portion includes a slidesituated in a track said slide having a central orifice for engagingsaid arm.
 13. The bi-directional clutch module of claim 12 wherein saidslide is actuated by hydraulics, pneumatics, a solenoid, a servo, a ballscrew arrangement, stepper motor, or the like for moving the slidingmember back and forth in the track for actuation said strut.
 14. Thebi-directional clutch module of claim 13 wherein said strut has apermanent magnetic characteristic and said frame includes a pin portionextending from said frame and having and insulated bobbin with anenergizable coil surrounding said bobbin, a U-shaped member including apair of actuation legs attached to said pin member and between said afirst polarized end of said strut and a second peripheral end of saidleg being adjacent to a second polarized end of said strut, such thatwhen said coil is energized the peripheral ends of said legs arepolarized for moving said strut to a first position and when energizedin an opposite direction the legs are polarized for moving the strut inan opposite direction.